1 files changed, 143 insertions, 0 deletions
diff --git a/mpm/python/usrp_mpm/eeprom.py b/mpm/python/usrp_mpm/eeprom.py
new file mode 100644
index 000000000..67920e885
--- /dev/null
+++ b/mpm/python/usrp_mpm/eeprom.py
@@ -0,0 +1,143 @@
+#
+# Copyright 2017 Ettus Research (National Instruments)
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+"""
+EEPROM management code
+"""
+
+import struct
+
+EEPROM_DEFAULT_HEADER = struct.Struct("!I I")
+
+class MboardEEPROM(object):
+    """
+    Given a nvmem path, read out EEPROM values from the motherboard's EEPROM.
+    The format of data in the EEPROM must follow the following standard:
+
+    - 4 bytes magic. This will always be the same value; checking this value is
+                     a sanity check for if the read was successful.
+    - 4 bytes version. This is the version of the EEPROM format.
+
+    The following bytes are version-dependent:
+
+    Version 1:
+
+    - 4x4 bytes mcu_flags -> throw them away
+    - 2 bytes hw_pid
+    - 2 bytes hw_rev (starting at 0)
+    - 8 bytes serial number (zero-terminated string of 7 characters)
+    - 6 bytes MAC address for eth0
+    - 2 bytes padding
+    - 6 bytes MAC address for eth1
+    - 2 bytes padding
+    - 6 bytes MAC address for eth2
+    - 2 bytes padding
+    - 4 bytes CRC
+
+    MAC addresses are ignored here; they are read elsewhere. If we really need
+    to know the MAC address of an interface, we can fish it out the raw data,
+    or ask the system.
+    """
+    # Create one of these for every version of the EEPROM format:
+    eeprom_header_format = (
+        None, # For laziness, we start at version 1 and thus index 0 stays empty
+        "!I I 16x H H 7s 25x I", # Version 1
+    )
+    eeprom_header_keys = (
+        None, # For laziness, we start at version 1 and thus index 0 stays empty
+        ('magic', 'eeprom_version', 'pid', 'rev', 'serial', 'CRC'), # Version 1
+    )
+
+class DboardEEPROM(object):
+    """
+    Given a nvmem path, read out EEPROM values from the daughterboard's EEPROM.
+    The format of data in the EEPROM must follow the following standard:
+
+    - 4 bytes magic. This will always be the same value; checking this value is
+                     a sanity check for if the read was successful.
+    - 4 bytes version. This is the version of the EEPROM format.
+
+    The following bytes are version-dependent:
+
+    Version 1:
+
+    - 2 bytes hw_pid
+    - 2 bytes hw_rev (starting at 0)
+    - 8 bytes serial number (zero-terminated string of 7 characters)
+    - 4 bytes CRC
+
+    MAC addresses are ignored here; they are read elsewhere. If we really need
+    to know the MAC address of an interface, we can fish it out the raw data,
+    or ask the system.
+    """
+    # Create one of these for every version of the EEPROM format:
+    eeprom_header_format = (
+        None, # For laziness, we start at version 1 and thus index 0 stays empty
+        "!I I H H 7s 1x I", # Version 1
+    )
+    eeprom_header_keys = (
+        None, # For laziness, we start at version 1 and thus index 0 stays empty
+        ('magic', 'eeprom_version', 'pid', 'rev', 'serial', 'CRC'), # Version 1
+    )
+
+
+def read_eeprom(
+        nvmem_path,
+        eeprom_header_format,
+        eeprom_header_keys,
+        expected_magic,
+        max_size=None
+):
+    """
+    Read the EEPROM located at nvmem_path and return a tuple (header, data)
+    Header is already parsed in the common header fields
+    Data contains the full eeprom data structure
+
+    nvmem_path -- Path to readable file (typically something in sysfs)
+    eeprom_header_format -- List of header formats, by version
+    eeprom_header_keys -- List of keys for the entries in the EEPROM
+    expected_magic -- The magic value that is expected
+    max_size -- Max number of bytes to be read. If omitted, will read the full file.
+    """
+    assert len(eeprom_header_format) == len(eeprom_header_keys)
+    def _parse_eeprom_data(
+            data,
+            version,
+        ):
+        """
+        Parses the raw 'data' according to the version.
+        Returns a dictionary.
+        """
+        eeprom_parser = struct.Struct(eeprom_header_format[version])
+        eeprom_keys = eeprom_header_keys[version]
+        parsed_data = eeprom_parser.unpack_from(data)
+        return dict(zip(eeprom_keys, parsed_data))
+    # Dawaj, dawaj
+    max_size = max_size or -1
+    with open(nvmem_path, "rb") as nvmem_file:
+        data = nvmem_file.read(max_size)
+    eeprom_magic, eeprom_version = EEPROM_DEFAULT_HEADER.unpack_from(data)
+    if eeprom_magic != expected_magic:
+        raise RuntimeError(
+            "Received incorrect EEPROM magic. " \
+            "Read: {:08X} Expected: {:08X}".format(
+               eeprom_magic, expected_magic
+       ))
+    if eeprom_version >= len(eeprom_header_format):
+        raise RuntimeError("Unexpected EEPROM version: `{}'".format(eeprom_version))
+    return (_parse_eeprom_data(data, eeprom_version), data)
+
+